1. Field of the Invention
The present invention relates generally to systems for processing hydrocarbonaceous materials and, more particularly, but not by way of limitation, to an improved system for treating feed mixtures to separate therefrom insoluble coal products.
2. Description of the Prior Art
Various coal processing systems have been developed in the past wherein coal has been treated with one or more solvents and processed to separate the resulting insoluble coal products from the soluble coal products, some systems including provisions for recovering and recycling the solvents.
U.S. Pat. Nos. 3,607,716 and 3,607,717, issued to Roach and assigned to the same assignee as the present invention, disclose processes wherein coal is contacted with a solvent and the resulting mixture then is separated into a heavy fraction containing the insoluble coal products and a light fraction containing the soluble coal products. In such processes, the light fraction is withdrawn and passed to downstream fractionating vessels wherein the soluble coal product is separated into multiple fractions. Other processes for separating the soluble coal products from the insoluble coal products utilizing one or more solvents are disclosed in U.S. Pat. No. 3,607,718, and 3,642,608, both issued to Roach et al., and assigned to the same assignee as the present invention.
U.S. Pat. No. 3,488,278, issued to Nelson, discloses a process for treating coal wherein coal is liquefied in a continuous countercurrent fashion. In that system, the crushed coal is introduced into an upper portion of a vertical vessel and a hydrogen-doner coal solvent is introduced at various vertically spaced positions in the lower portion of the vessel. The coal settles through the solvent to produce a residue stream containing ash and undissolved material in the lower portion of the vessel. U.S. Pat. No. 2,987,465, issued to Johanson, discloses a process wherein a liquid hydrocarbon and a hydrogen rich gas are passed upwardly through a mass of solids for producing a liquid effluent of hydrogenated carbon containing material, the Johanson patent disclosing a process for contacting a gas with liquids in the presence of solids.